Differences between Sympathetic and Parasympathetic nervous system on the basis of function:
| Sympathetic nervous system | Parasympathetic nervous system |
|---|---|
| Sympathetic nervous system produces immediate fight or flight responses against abnormal conditions. | The parasympathetic nervous system re-establishes the normal conditions of the body after a fight or flight response. |
| For example, sympathetic nervous system may increase the heart rate to meet the oxygen demand of the body during abnormal conditions. | For example, parasympathetic nervous system relaxes the heart rate after the abnormal situation has passed. |
Chapter 8: Human Body: Nervous System — ICSE Class VII Biology Notes
Comprehensive ICSE Class VII Biology notes on the Human Nervous System covering brain parts (cerebrum, cerebellum, medulla), spinal cord, neuron structure, reflex action, reflex arc, and voluntary vs involuntary actions.
Key Concepts and Topics
Topics covered: Brain, Spinal cord, Neurons, Reflex action, Reflex arc
Weightage: Approximately 8 marks in the exam
Important Points to Remember
- CNS = brain + spinal cord; PNS = nerves
- Brain parts: cerebrum (thinking), cerebellum (balance), medulla (involuntary)
- Neuron: cell body + dendrites (receive) + axon (transmit)
- Reflex action: automatic response controlled by spinal cord
- Reflex arc: receptor to sensory nerve to spinal cord to motor nerve to effector
- Brain protected by skull, meninges, and cerebrospinal fluid
- Voluntary actions involve brain; reflex actions bypass brain
Frequently Asked Questions
Q: What is a reflex action?
A: A quick, automatic, involuntary response to a stimulus, controlled by the spinal cord without involving the brain.
Q: What are the three main parts of the brain?
A: Cerebrum (thinking), Cerebellum (balance), and Medulla oblongata (involuntary actions).
Q: What is a reflex arc?
A: The pathway of a reflex: Receptor → Sensory nerve → Spinal cord → Motor nerve → Effector.
Exam Preparation Tips
- Focus on understanding concepts rather than rote memorization
- Practice drawing and labelling diagrams regularly
- Use comparison tables for topics that require differentiation
- Solve previous year questions and practice papers
- Review the chapter notes provided by Bright Tutorials for comprehensive coverage
For complete chapter notes, practice questions, and test papers, contact Bright Tutorials at 9403781999.